Painting the Gonzaga-Montefeltro Chest

Introduction

This travelling chest bears the coats of arms of Elizabetta Gonzaga of Mantua (1471–1526) and Guidobaldo da Montefeltro, Duke of Urbino (1472–1508). The couple were betrothed in 1486 and married in 1488. This may have been one of ten similar chests made for their use during the wedding preparations and formalities, and recorded in an inventory of Elisabetta’s trousseau corredo, compiled around 25th February 1488: ‘Venti forzieri, dieci lavorati d’oro, dieci depinti a la divisa’ (twenty chests, ten gilded, ten painted with heraldic arms/devices).

Conservation carried out in 2009-10 revealed the full effects of the wide range of colours and painterly techniques used to decorate the chest. Many of the techniques used are those described by Cennino Cennini in his treatise on painting ‘Libro dell’arte’ (probably written in the early 15th century), as used by the painters of flat panel paintings in 14th century Italy. (Cennini, chapter CLXX ‘Come deí lavorar cofani o vero forzieri, e il modo di adornarli e colorirli.’)

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  Gonzaga-Montefeltro chest conservation

  (a) Front left foot, showing stages in cleaning and retouching

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  Gonzaga-Montefeltro chest conservation

  (b) Front left foot, showing stages in cleaning and retouching

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  Gonzaga-Montefeltro chest conservation

  (c) Front left foot, showing stages in cleaning and retouching

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  Gonzaga-Montefeltro chest conservation

  (d) Front left foot, showing stages in cleaning and retouching

Timber

Poplar planks were used, as they would have been easily available, were not prone to warp and having a fine grain, providing a smooth surface for painting.

The curved front of the cassone was cut from a solid block. Once the surface was smoothed flat it provided a sound base for the ‘ground’ layer of preparation.

The front and back (about 22mm thick) are both cut from single large boards. These were nailed onto the two sides (including the integral foot), which are both cut from single pieces of wood. (The front bracket ‘feet’ are decorative and added.) Front, back and sides were nailed onto the single board that forms the bottom of the chest.

 

The curved lid was constructed using three planks with their edges slightly angled and butted (and probably glued) together, nailed onto a shaped end piece. A shaped moulding was applied along the front edge of the lid. Remarkably, the chest is structurally in almost original condition. Only minor repairs have been needed where some of the joints have opened (between the planks of the lid, for example), and on the right foot, where a small section of the bracket has been lost.

Nails

Cut iron nails (with roughly rectangular heads) were driven below the surface of the planks and their heads concealed with a white calcium-based preparatory ground before painting. Some of these gesso plugs have been lost as the nails caused them to fall out once they had grown rusty. Cennini’s recommendation (Cennini, chapter CXIII) that a small piece of sheet tin be placed over the nail head to prevent this problem, was not followed on this chest.

 

The lid is held on the three original iron ring hinges, the type known in Italy as gangherelli.

At each end several relatively modern nails have been fixed into the flange, possibly to secure a textile cover for the lid.

The Painted Surfaces

For the painted surfaces the bare wood was treated as follows: it would have been first ‘sized’ with a mixture of animal glue and water (Cennini, chapter CXIII), then prepared with layers of ‘ground’ which were covered, where metal leaf was to be applied, with layers of red bole. (According Cennini in chapter CXXXI, bole consisted of haematite and clay mixed with water and egg-white).

Areas of exposed ground are visible along the front edge of the lid, and were toned down so as not to appear obtrusive.

When the cassone was painted, the traditional technique used was tempera, but the quality and appearance of the cassone (where paint has been applied more thickly and freely) suggests that the craftsman may have mixed pigments with oil as a medium, or a mixture of egg-yolk and oil, known as tempera grassa.

Gold and silver

The gilded areas were created with gold leaf applied to the wetted bole (the technique known as water gilding, described by Cennini in chapter CXXXIV). Large sheets of gold leaf (22cm square) were used in Italy at this time. Variegated textures to the gold were then produced by burnishing, punching (Cennini chapter CXL), or scratching away through an overlayer of resin. There is no evidence of an original varnish on the chest, and in fact Cennini recommends that varnish should not be applied over gilding because the gold ‘does not like the varnish’ (“[…] guarti di non andare di sopra all’oro, che non gli piace compagnia di vernice, nè d’altri licori.” chapter CLV). He recommends waiting at least a year after painting, before varnish is applied to these painted parts. Some areas such as the censer and coat of arms were originally silver, created using silver leaf. Most of this has worn away or tarnished (which cannot be reversed), so it appears dark.

Green

The green is a copper green (Cennini chapter LVI) applied over an earlier, paler green with yellow ochre, traces of which remain. At some point, another green pigment was applied over the top which darkened over time, and has been removed (before and after shots).

 

Orange

On the curved flanges at both ends of the lid and on the foot brackets, a russet red lake was applied over yellow and red (orpiment and cinnabar), and enhanced with yellow leafy scrolls.

This red has darkened as the red lake has aged, and a tiny mosaic of cracks (or craquelure) has formed.

 

Sequence of Decoration

• Bare wood
• Gesso layer on which setting-out compartments are incised
• Red bole under areas to be gilded or silvered
• Silver leaf
• Gold leaf and indigo over the leaf. Leaf burnished.
• Background pink and azurite
• Sgraffito work
• Black border lining on the censer motifs and letters A
• Punching
• Painting of the heraldic devices (the red and white flames and white/red/green scales)
• Black and yellow definition of ‘carved’ mouldings
• Final touches (No evidence was found of an original varnish)